2i6 VENOMOUS ANIMALS: PROTOZOA TO ARTHROPODA 



of secretion into the victim, but the nature of this fluid and its 

 action requires further investigation. Nuttall, drawing attention 

 to the immunity following bites, says that it is probable that this 

 secretion is toxic in its action. 



The Effects of the Venom.— With regard to the Argasid^, Argas 

 persicus Oken has an evil reputation in Persia, where its bite is said 

 to cause severe pain, fever, lassitude, delirium, convulsions, and 

 even at times death in new-comers, while natives are immune. 



Bordier considers that these symptoms are due to the injection 

 of a poison, but this would hardly appear to be likely, as Louns- 

 bury found in his own case in South Africa that the bite 



caused only slight itching. 

 If the symptoms are properly 

 described in Persia, it would 

 indicate that the tick intro- 

 duced some parasite into 

 the new-comer which caused 

 a definite disease to which 

 the native had acquired an 

 immunity. 



Fig. 1 8. — Ventral Aspect of the Mouth- 

 Parts OF A Tick {HcBmaphy salts punc- 

 tata Canestrini and Fanzago) . 



(After Nuttall, Cooper, and Robinson, 

 Journal of Parasitology.) 



I, Chelicerae, showing teeth; 2, hypostome, 

 showing rows of recurved teeth; 3, palp. 



Fig. 19. — Chelicera from the 

 Same Tick. 



(After Nuttall, Cooper, and 

 Robinson, Journal of Parasi- 

 tology.) 



I, Internal digit; 2, external 

 digit. 



Argas reflexus Fabric ius may cause local pain and swelling, with 

 sometimes an erythematous eruption, while the site of the bite is 

 marked for years by a cicatrix. The bite of A. brumpti Neumann 

 is also severe. 



Ornithodoros moubata Murray inflicts a very painful bite, with 

 much swelling and the formation of raised hard wheals, in Euro- 

 peans, which may last several days. 



Ornithodoros turicata Duges may cause swelling and numbness 

 all over the body, with vomiting and diarrhoea, accompanied by 

 an urticarial eruption and profuse perspiration, with rigors, fever. 



